Strontium

Description

Standard State: solid at 298 K
Color: silvery white

Isolated by Davy by electrolysis in 1808; however, Adair Crawford in 1790 recognized a new mineral (strontianite) as differing from other barium minerals (baryta).   Strontium is found chiefly as celestite and strontianite.   The metal can be prepared by electrolysis of the fused chloride mixed with potassium chloride, or is made by reducing strontium oxide with aluminum in a vacuum at a temperature at which strontium distills off. It does not absorb nitrogen below 380°C.  It should be kept under kerosene to prevent oxidation.  The finely divided metal ignites spontaneously in air. Natural strontium is a mixture of four stable isotopes.  Sixteen other unstable isotopes are now to exist.  Of the  greatest  importance, the principle Sr element has a half life of 29 years.  It is a product of nuclear fallout and presents a health problem.   It has also found use in producing ferries magnets and in refining zinc.